Retention grommet



FIG. 1 is a top, front perspective view of a first embodiment of a retention grommet according to the present design;

FIG. 2 is a bottom, back perspective view

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a left-side view thereof;

FIG. 6 is a right-side view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The dashed broken lines depict portions of the retention grommet that form no part of the claimed design. The dot-dashed broken lines represent boundaries of the claimed retention grommet and form no part of the claimed design. 

CLAIM The ornamental design for a retention grommet, as shown and described. 